1. Technical Field
The present invention relates to a voice processing apparatus and a voice processing method for detecting and correcting an error of voice data.
2. Description of Background Art
In a cordless telephone or a PHS (Personal Handy-phone System), differential voice data which is quantized through an ADPCM scheme is transmitted or received in the unit of transmission frame. The “quantized differential voice data” as used in this specification refers to a differential value of an actual measurement value to an estimated value, and the received voice data is decoded as a voice to be outputted.
JP-A-8-288914 discloses an error processing method of suppressing noise in the PHS, in which voice data is determined whether or not there is an error in a transmission frame and a value of the voice data which is determined that there is an error in the transmission frame is converted to “0” or a small value.
However, in the error processing method described in JP-A-8-288914, when the error is detected in the voice data of the transmission frame, regardless of a level of the error, the voice data is simply converted to a value even though the error is minor. For this reason, all the voice data in which the error is detected are converted to “0” or a value close to zero. Converting the value of the voice data which is a differential value to “0” or a value close to zero means that a decoded voice is muted or faded out. Further, even though the noise is suppressed, the voice to be originally outputted is also muted, so that there was a problem that recognition of the original voice is difficult.
The present invention is made in view of the above circumstances, and an object is to provide a voice processing apparatus and a voice processing method which can easily recognize an original voice while suppressing noise.